Internal explosion within 12V forklift battery
- Safety Flash
- Published on 1 September 2003
- Generated on 20 November 2025
- IMCA SF 11/03
- 2 minute read
A forklift battery was found to be flat and it was changed out with a replacement that was held onboard and tested per procedures, the forklift was also function tested and all were working satisfactorily.
What happened?
The following morning the pre-start up checks on the forklift were carried out, and no problems were identified. The forklift operator than attempted to start the engine. As he did this he heard a loud noise from behind him, he immediately switched off the engine, and turned to see vapour and electrolyte spilling from the battery compartment. The spill was contained, and the electrician was called to make the area safe by disconnecting the battery. The battery was found to have a ruptured cell and was returned to the supplier to determine the cause of the failure. The battery was a 12 volt, sealed, lead acid type.
On inspection it was found that the cell plates within the battery had sulphated and dried, the mud space was also found to be full, which is a natural process with age and this combination had led to an internal explosion. The failure occurred inside the battery enclosure, which protected personnel from flying battery case particles and electrolyte. The electrolyte that spilled had drained from two holes in the base of the battery compartment.
The company involved has made the following recommendations:
- Change out all batteries of sealed lead acid type annually.
- Future permits to work (PTW) and maintenance procedures should take this incident into consideration, if jump starting or fault diagnosis is carried out with the battery exposed.
IMCA Safety Flashes summarise key safety matters and incidents, allowing lessons to be more easily learnt for the benefit of the entire offshore industry.
The effectiveness of the IMCA Safety Flash system depends on the industry sharing information and so avoiding repeat incidents. Incidents are classified according to IOGP's Life Saving Rules.
All information is anonymised or sanitised, as appropriate, and warnings for graphic content included where possible.
IMCA makes every effort to ensure both the accuracy and reliability of the information shared, but is not be liable for any guidance and/or recommendation and/or statement herein contained.
The information contained in this document does not fulfil or replace any individual's or Member's legal, regulatory or other duties or obligations in respect of their operations. Individuals and Members remain solely responsible for the safe, lawful and proper conduct of their operations.
Share your safety incidents with IMCA online. Sign-up to receive Safety Flashes straight to your email.